The present invention relates a structure for wireless communication in an electromagnetically shielded building, and more particularly to a structure for wireless communication in a building with its interior space electromagnetically shielded from the exterior space thereof so that the radio waves propagating in the exterior space are preventing from intruding into the interior of the building and those propagating in the interior space are prevented from leaking out to the exterior space, thereby making it possible to select wavebands freely within the building or on each of floors of a tall multistory building or in each of rooms of the building for wireless communication.
Generally, where wireless communication is effected only within a building by means of wireless devices disposed in the building, the radio waves transmitted from the exterior space of the building tend to intrude into the building through the windows even through the walls of the building are made of materials such as concrete which attenuate and cut off the ratio waves, for the windows are composed of glass panes which are not electromagnetically shielded. Further, when the transmitting output power of a wireless device located in the building is increased, the radio waves from the wireless device are radiated out of the building through the electromagnetically unshielded window glass panes and interfere with radio waves outside of the building. In case the output power of a wireless device is such that the radio wave transmitted therefrom has a field intensity lower than a certain level, it is impossible to obtain a sufficient S/N (signal to noise) ratio by means of communication systems utilizing common modulation methods, resulting in deteriorated communication quality. To avoid this disadvantage, wireless devices of higher output power become necessary. The supply and demand in the VHF and UHF frequency ranges which can preferably be used by these high power wireless devices, however, are so tight that it is difficult to use wireless devices in these frequency bands which realize high quality communication.